Richard Guo <guofengli...@gmail.com> 于2024年6月18日周二 17:24写道：
> On Tue, Jun 4, 2024 at 6:51 PM Tender Wang <tndrw...@gmail.com> wrote: > > Yeah, Richard commented the v1 patch about JOIN_UNIQUE_INNER in [1] > > > > * I think we should not consider materializing the cheapest inner path > > if we're doing JOIN_UNIQUE_INNER, because in this case we have to > > unique-ify the inner path. > > > > We don't consider material inner path if jointype is JOIN_UNIQUE_INNER > in match_unsorted_order(). > > So here is as same logic as match_unsorted_order(). I added comments to > explain why. > > I looked through the v4 patch and found an issue. For the plan diff: > > + -> Nested Loop > + -> Parallel Seq Scan on prt1_p1 t1_1 > + -> Materialize > + -> Sample Scan on prt1_p1 t2_1 > + Sampling: system (t1_1.a) REPEATABLE (t1_1.b) > + Filter: (t1_1.a = a) > > This does not seem correct to me. The inner path is parameterized by > the outer rel, in which case it does not make sense to add a Materialize > node on top of it. > Yeah, you're right. > > I updated the patch to include a check in consider_parallel_nestloop > ensuring that inner_cheapest_total is not parameterized by outerrel > before materializing it. I also tweaked the comments, test cases and > commit message. > Thanks for the work. Now it looks better. I have changed the status from "need review" to "ready for commiters" on the commitfest. -- Tender Wang
